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Biomedical subjects

K Laiho

Publications and source records attributed to K Laiho.

At least 55 records · Page 3Linked to original sources
PubMed1998

Variations in faecal bacterial enzyme activities and associations with bowel function and diet in elderly subjects.

Daily and inter-individual variations of faecal bacterial beta-glucuronidase and beta-glucosidase activities and their associations with parameters of bowel function were studied in 10 residents of an old people's home during two 1-week periods 2 weeks apart. The effect of sampling method (a spot sample vs an aliquot of the homogenized sample from a total daily collection) on the activities of these enzymes and that of urease was also assessed. Intestinal transit time was determined using the radio-opaque Sitzmark; capsules, and questionnaires on bowel function and intakes of fluids and fibre-containing foods were completed. The mean (95% confidence interval) beta-glucuronidase and beta-glucosidase levels were 3.08 (2.75-3.41) and 11.53 (10.79-12.26) nmol min-1 mg protein-1. Daily variations in enzyme activities within individuals were not significant (P = 0.277 and 0.990, respectively), whilst those between individuals were highly significant (P = 0.000). Faecal frequency correlated negatively with beta-glucuronidase and urease, but no other associations of the enzyme activities with parameters of bowel function and diet were observed. beta-Glucuronidase and beta-glucosidase were not affected by the sampling method, while significantly higher urease was obtained by spot sampling as compared with the aliquot representing the total daily collection. Large inter-individual variations in faecal enzyme activities should be taken into consideration when planning experiments and interpreting results on these faecal parameters.

Aged↗
PubMed1989

Removal of contaminating hemoglobin from peroxidase in traumatic skin lesions.

A method is described for the removal of contaminating hemoglobin from the peroxidase enzyme in traumatic skin lesions. The procedure is based on hemoglobin precipitation in a combination of ammonium sulfate half-saturation, and chloroform shaking of the cetyltrimethylammonium-bromide extract. The procedure as such somewhat increases the activity of the peroxidase extract if the extract contains no hemoglobin. On the other hand, the peroxidase activity of the extract decreases as the amount of precipitating hemoglobin increases. On average, about 90% of the peroxidase activity persists after hemoglobin precipitation if the hemoglobin concentration in the extract does not exceed 25 mg/100 ml. In experimental incision wounds, the peroxidase activities obtained with this procedure were the same as when enzyme determinations were done without the removal of hemoglobin or slightly higher. In addition, the amount of peroxidase activity in the wounds was estimated, based on the granulocytes of the contaminating blood.

Animals↗
PubMed1988

Peroxidase activity in traumatic skin lesions.

Peroxidase activity was determined in experimental compression-excoriation lesions and incision wounds of rat skin after different periods of vital time. The peroxidase enzyme was extracted from the tissues by homogenization in 0.5% cetyltrimethylammoniumbromide, and the enzyme activity was measured from the supernatant by o-dianisidine-H2O2 assay. In the blood of the rats a mean activity of approx. 5.26 +/- 1.11 U/g dry weight was observed. In the control specimens of the skin the activity was very low and generally below the detection limit of the methods used. In 30-min-old compression-excoriation lesions the mean peroxidase activity was 0.38 +/- 0.21 U/g dry weight. In lesions older than 30 min the activity started to increase rapidly. In 4-h-old compression-excoriation lesions it was 10 times higher than the 30-min level and was 40 times higher in 12-h-old lesions and 70-100 times higher in 1-3-day-old compression-excoriation lesions, respectively. In 30-min-old incision wounds the mean peroxidase activity was 0.65 +/- 0.37 U/g dry weight. The increase of the activity compared with the 30-min level was even faster in the incision wounds: in 4-h-old wounds the mean activity was 50 times higher, in 12-h-old wounds 200 times higher and in those of 1-5 days it was several hundreds of times higher. Compression-excoriation lesions made after death showed activity similar to the control specimens. Postmortem autolysis at +22 degrees C resulted in a loss of the enzyme activity in 1-day-old compression-excoriation lesions so that after 3 days approx. 80% remained, and after 5 and 7 days approx. 40% was present. After 3 days of autolysis at +4 degrees C, nearly 100% of the activity remained and approx. 90% was present after 5 and 7 days of autolysis. Increased peroxidase activity was also detectable in human vital excoriations in the specimens which were taken in autopsies several days postmortem.

Animals↗
PubMed1987

Extractable iron in experimental hematomas.

The extractable iron and total iron were determined in experimental, subcutaneous hematomas (5 ml blood) of rats after different periods of vital time. The extractable iron was determined from homogenate extract obtained after 24-h incubation with concentrated HCl diluted 1:3 and protein precipitation. For the determination of total iron, the specimens were wet-ashed. The same iron determinations were also made for the corresponding control specimens of the subcutaneous tissue. Extractable iron started to rise over the control values in 2-day-old hematomas, being about 5 times higher after 3 days, about 15 times higher after 7 days, and about 20 times higher after 14 days. The ratio of extractable iron and total iron expressed as percentages was about 1% in 1-h and in 1-day-old hematomas, about 20% in 3-day-old hematomas, about 50% in 7-day-old hematomas, and about 65% in 14-day-old or older hematomas. The effect of autolysis for 3 days at room temperature was studied on 1-h-old hematomas. Extractable iron values were slightly higher in the autolyzed specimens, but the difference was statistically insignificant as compared to specimens taken immediately after death.

Animals↗
PubMed1984

Hemoglobin-degrading enzymes in experimental subcutaneous hematomas.

The activities of heme oxygenase and biliverdin reductase were determined in subcutaneous (s.c.) hematomas of rats after different periods of vital time. The postmortem stabilities of the heme-degrading enzymes were also studied by keeping the rats with vital hematomas for 1-5 days at temperatures of +4 degrees C and +22 degrees C. A tenfold increase of heme oxygenase activity over the starting level was observed in 2-9-day-old vital hematomas, when the specimens were taken immediately after death. Biliverdin reductase showed only negligible changes. Postmortally, heme oxygenase activity started to decrease in hematomas immediately at +22 degrees C and from day 2 on at +4 degrees C.

Animals↗
PubMed1984

Plutonium in Finnish Lapps--an estimate of the gastrointestinal absorption of plutonium by man based on a comparison of the plutonium content of Lapps and southern Finns.

The plutonium body burden of five male Lapps was determined through radiochemical analysis of bone, liver and lung samples, and compared with the body burden of male southern Finns. Tissue burdens of plutonium were found equal in the Lapps and southern Finns. The mean content of 239,240Pu in bone (ribs), liver and lung of the Lapps was 0.045, 0.42 and 0.033 pCi/kg wet wt (1.7, 15.5, 1.2 mBq/kg), respectively. The average body burden of plutonium in the Lapps was 1.1 pCi (41 mBq). The 137Cs, 90Sr, 210Po and 210Pb contents of tissue samples were analyzed to estimate the amount of reindeer tissue consumed by the Lapps studied. The 137Cs content in liver and lung of the Lapps was, on the average, 2160 and 1180 pCi/kg wet wt (79.9 and 43.7 Bq/kg), respectively. In southern Finns both liver and lung content of 137Cs was less than 50 pCi wet wt (less than 1.9 Bq/kg). For 210Po, the liver and lung values were 86.2 and 8.2 pCi/kg wet wt (3.2 and 0.3 Bq/kg) in the Lapps and 15.4 and 3.9 pCi/kg wet wt (0.6 and 0.1 Bq/kg) in southern Finns, respectively. The inhalation intake of 239,240Pu of male Lapps during the period 1954-1978 was about 13 pCi (0.48 Bq) and that of southern Finns about 18 pCi (0.67 Bq). The estimated values for dietary intake were 535 pCi (19.7 Bq) and 36 pCi (1.3 Bq), respectively. The fractional absorption factor of 239,240Pu from the GI tract of man was estimated to be (8-9) X 10(-4), which is somewhat higher than that presently suggested by the ICRP for soluble plutonium compounds (1 X 10(-4)).

Adult↗
PubMed1975

Haemostatic plugs as a histological vital reaction in the skin wounds of guinea pigs.

Applying a histological staining method (Carstairs' modification of picro-Mallory staining), haemostatic plugs could be demonstrated at points of vascular lesion in one-minute vital, or older, skin wounds of the guinea-pig on the average in 33% if the specimen was taken immediately after the reaction period, and in about 10% of wounds examined if the specimen was taken five days after death. No haemostatic plugs could be observed in postmortally inflicted skin wounds.

Animals↗